専せん門もん外がい

noun which may take the genitive case particle 'no', noun

outside one's area of expertise; outside one's field

Used to indicate that something is not within one's professional or academic specialty. Often appears in the pattern 専門外の〜 or 専門外で〜.

• その質しつ問もんは私わたしの専せん門もん外がいです。